Screening colonoscopy volume and detection of colorectal neoplasms: a state-wide study from Bavaria, Germany

Screening colonoscopy enables early detection of colorectal cancer and its precancerous lesions. The aim of this study was to assess the association of screening colonoscopy volume with colorectal neoplasm detection rate in routine practice. A registry-based study of individuals aged at least 55 years who underwent screening colonoscopy in Bavaria, Germany, between 2007 and 2009 was performed. Colorectal neoplasm detection rates (95% confidence intervals) were determined per physician. Physicians were grouped according to the number of screening colonoscopies performed per year (<50, 50-99, 100-199, ≥200). A total of 203 363 individuals (median age 64 years, 55.2% women) underwent screening colonoscopy between 2007 and 2009. Colonoscopies were performed by 509 physicians. The detection rate of any neoplasm increased with screening colonoscopy volume from 21.9% among physicians conducting fewer than 50 screening colonoscopies per year to 27.5% among physicians conducting 200 or more screening colonoscopies per year (P-value for trend <0.0001). Increases in detection rates with colonoscopy volume were also observed for advanced neoplasms and for colorectal cancer (P-value for trend 0.16 and <0.0001, respectively). Differences were largest between physicians conducting fewer than 50 screening colonoscopies per year and other physicians. These results support a potential role of a minimum colonoscopy volume for high-quality colonoscopy screening. Differences in neoplasm detection rates were high between physicians conducting fewer than 50 screening colonoscopies per year and physicians with higher screening colonoscopy volume.